1. Field of the Invention
This invention relates to a method of treating sickle cell anemia and, more specifically, it relates to a method of resisting sickling of hemoglobin in a sickle cell anemia patient.
2. Description of the Prior Art
Sickle cell anemia is a hereditary blood disease which can afflict African, Mediterranean and Mideastern peoples. The anemia results from the physical aggregation of a mutant hemoglobin protein constituent in red blood cells. This aggregation results in a distortion in shape of deoxygenated red blood cells and causes impairment of flow of the blood through the capillaries (sickle cell "crises"). As the principal function of hemoglobin is to transport oxygen from the lungs to body tissues, efficient flow of oxygen throughout the body's tissues is impeded by the anemia due to a lower number of red blood cells. Sickle cell anemia also may have an indirect effect on the heart, lungs, kidneys, spleen, hips and brain. Sickle cell anemia crises can be extremely painful, can result in infections such as pneumonia, can result in skin ulceration, can contribute to strokes and seizures in the one afflicted and can also result in the development of chronic bone infections.
In general, the result of the differences between cells containing hemoglobin A, the normal hemoglobin, and hemoglobin S, the sickle cell hemoglobin, is that the former cell is generally flexible and bioconcave discoid in shape, while the latter is more rigid and crescent shaped and typically has pointed ends. This rigidity and distortion in shape causes the cells to be lodged in the capillary. Hemoglobin molecules contain two beta polypeptide chains and two alpha polypeptide chains. In the sickle cell hemoglobin, a mutation is present in the beta chains. More specifically, the sixth amino acid of each beta chain is changed from glutamic acid to valine. As a result of this mutation, hemoglobin S upon deoxygenation polymerizes and causes the cell to assume the elongated, sickle-like configuration. As the sickle cells have a much shorter life span than normal red cells, the effect on the body is to deplete the total volume of blood cells thereby creating an anemic condition.
Electrophoresis is one of the well established laboratory tests employed in diagnosing sickle cell anemia. Electrophoresis tests determine whether an individual has sickle cell anemia (homozygous) or merely the sickle cell trait (heterozygous). The latter refers to an individual not having the disease but having the capability of transmitting the disease to offspring if mated to anoter heterozygote. Treatment for the various complications which have resulted from sickle cell anemia are known and should be distinguished from prophylactic treatment generally (unknown) which would eliminate the occurrence of the complications and adverse symptoms. Currently, symptomatic treatment is available. For example, one can treat the symptoms by using analgesics for pain, and antibiotics for infection, but these approaches do not arrest the underlying sickling phenomena.
There remains, therefore, a very real and substantial need for a treatment method which minimizes the adverse consequences of sickle cell anemia by directly inhibiting the underlying cause of sickle cell crises.